Sustainable design in Atwater Commons
Atwater Commons is a great example of sustainable design on Middlebury's campus. Both the dining hall and the newest residence halls were designed with sustainability as a high priority without sacrificing functionality or comfort. For more details about sustainable design in these building, check out the Atwater Dining Hall and Atwater Residence Halls pages in the left-hand navigation bar.
Atwater Dining Hall
Atwater's most notable feature is its green roof, which uses shrubs and grasses to cover the roof. This increases storm water retention, improves insulation, provides moderate replacement to lost habitat. Because native plants species are used, maintenance of this system is minimal. The dining hall also employs daylighting, energy efficiency features, and FSC certified wood.
Benefits of the Green Roof
- Storm water management. Green roofs retain 70 to 100% of rainwater in the summer and 40 to 50% in winter. Excess water flows through the storm system and is cleansed by filtration though the plants and soil.
- Improved thermal insulation. Excess heat often present on a conventional gravel-ballasted roof is absorbed and re-radiated, substantially lowering air-conditioning costs. In winter, the added insulative layer of soil and plantings reduce heat loss, resulting in diminished heating costs.
- Extended durability of waterproofing. The insulative value of the green roof system also serves to protect the waterproofing layer from damaging ultraviolet radiation, prolonging the lifespan of the waterproofing system.
- Improved acoustical insulation. Green roof systems can reduce airborne sound levels by 40 to 50 decibels.
- Minimized development impact. The vegetation on the green roof provides moderate replacement to lost habitat and is an aesthetic improvement compared to conventional roofing materials.
- Extensive system. The low maintenance extensive green roof system supports exclusively native species of herbaceous plants and ground cover shrubs.
Atwater Commons Residence Halls
Known on campus as the Atwater Suites, the two newest building additions to Atwater Commons use an innovative ventilation system to cut down on energy use without sacrificing thermal comfort. Additionally, the sites for the buildings were chosen to minimize visual impact and reduce impervious surface area, and much of the building material used was recycled.
How does the ventilation system work?
- The buildings are oriented with their longest sides facing east-west to take advantage of seasonal prevailing winds.
- Masonry walls add mass and act as a thermal sink for cooler air.
- The suites are designed to allow for cross-ventilation.
- Transoms above doorways allow air flow between bedrooms and common spaces.
- All spaces are equipped with ceiling fans to assist air flow and all windows have operable shades.
- The high (11’-4”) ceilings help to stratify warmer air from cooler air.
- Vertical ventilation stacks offer mechanical assistance in the removal of air from each suite by an individually controlled attic fan that exhausts air through chimneys and draws in cooler air though windows.